function U = Variables2U(rou,u,v,p)
% VARIABLES2U - 将物理量转化成守恒变量
%   

U = zeros(4,1);
U(1) = rou;
U(2) = rou*u;
U(3) = rou*v;
U(4) = (p/0.4)+(u^2+v^2)*rou/2;
